1911 Encyclopædia Britannica/Hai
HAI (939-1038), Jewish Talmudical scholar, was born in 939. He was educated by his father Sherira, gaon of Pombeditha (Pumbedita), whom he afterwards assisted in his work. They were cast into prison for a short time by the caliph Qadir, and subsequently on Sherira's death Hai was appointed gaon in his place (998). This office he held till his death on the 28th of March 1038. He is famous chiefly for his answers to problems of ritual and civil law. He composed important treatises on Talmudic law and the Mishnah; many poems are also attributed to him on doubtful authority. In his responsa he laid stress on custom and tradition provided no infringement of the law were involved, and was essentially conservative in theology. He had considerable knowledge not only of religious movements within the Jewish body, but also of Mahommedan theology and controversial method, and frequently consulted theologians of other beliefs.
See Steinschneider, Hebr. Übersetz. p. 910, and article in Jewish Encyclopedia, vi. 153.